Claude Sonnet 4.5 vs GPT OSS 120B
Compare Claude Sonnet 4.5 by Anthropic against GPT OSS 120B by OpenAI, in 25 community votes, claude sonnet 4.5 wins 70% of head-to-head duels, context windows of 200K vs 131K, tested across 43 shared challenges.
Web Design: Claude Sonnet 4.5 and GPT OSS 120B are tied
Reasoning: Claude Sonnet 4.5 wins 71% of votes
Image Generation: Claude Sonnet 4.5 wins 100% of votes
Our Verdict
Claude Sonnet 4.5Winner
GPT OSS 120BRunner-up
Pick Claude Sonnet 4.5. In 25 blind votes, Claude Sonnet 4.5 wins 70% of the time. That's not luck.
Claude Sonnet 4.5 particularly excels in Image Generation, Reasoning. GPT OSS 120B is 19x cheaper per token — worth considering if cost matters.
Clear winner
API pricing
Cost per 1M tokens
Claude Sonnet 4.5
Input
$3.00
Output
$15.00
GPT OSS 120B
Input
$0.18
17× cheaper
Output
$0.80
19× cheaper
GPT OSS 120B is cheaper on both — 17× input, 19× output
Writing DNA
Style Comparison
Similarity
39%
Claude Sonnet 4.5 uses 4.9x more sentence length
Claude Sonnet 4.5
GPT OSS 120B
64%Vocabulary52%
94wSentence Length19w
0.48Hedging0.28
4.9Bold7.4
8.0Lists1.8
0.45Emoji0.15
1.91Headings0.73
0.07Transitions0.17
Based on 20 + 21 text responses
Research
What we learned reading every model
FAQ
